A pneumatic ball launcher includes a tube, a ball pathway unit, a push unit, a holding unit, an airway unit and a pneumatic unit. The ball pathway unit is used for connecting one end of the tube and wrapping part of a ball channel of the tube. The push unit includes a push bar, a slide base, a first driver and a second driver. The holding unit, detachably connected with the push unit, is used for holding the ball pushed by the push bar. The airway unit is connected with the holding unit. The pneumatic unit includes a valve mechanism, a pneumatic cylinder and a gas tank. When the valve mechanism opens to allow the gas tank to discharge into the holding unit via the airway unit, the ball held by the holding unit would be ejected out of the tube.

Systems, methods and computer-readable media are provided for determining an effective altitude in relation to a moving sports object. In some examples, a method includes determining respective values for an air temperature, an air pressure, and a relative humidity of an environment of interest. Based on the determined respective values of the air temperature, the air pressure, and the relative humidity, an air density for the environment of interest is calculated to derive a first air density value. A second air density value is derived for a reference environment. An absolute value of a difference between the first and second air densities is compared against a preset comparison value and, based on the comparison being equal to or smaller than the preset comparison value, an output including an indicator of the effective altitude is generated.

A system is disclosed that includes a ball-throwing machine included within a first housing, a controller communicatively coupled to the ball-throwing machine and included within a second housing different than the first housing, a camera, and a non-transitory storage medium having stored thereon logic, the logic being executable by one or more processors to perform operations including: receiving information associated with a selection of a first training drill from the controller, responsive to receiving the information associated with the selection of the first training drill, causing the ball-throwing machine to impart motion to one or more balls in accordance with the first training drill, receiving multimedia data of a player captured by the camera, and performing a player recognition procedure to locate the player within the multimedia data.

In a first aspect, a method for monitoring a golf swing is provided that includes coupling a mobile telephone to a golf club and employing the mobile telephone coupled to the golf club to monitor acceleration of the mobile telephone as the mobile telephone swings while a user swings the golf club, collect acceleration information based on the monitored acceleration of the mobile telephone as the mobile telephone swings, analyze the collected acceleration information to determine one or more characteristics of the golf swing based on the collected acceleration information, and output information regarding the one or more characteristics of the golf swing on the display of the mobile telephone. Numerous other aspects are provided.

A bag includes a main compartment configured to accommodate equipment, and a foldable chair compartment disposed adjacent to the main compartment. The foldable chair compartment is configured to accommodate a foldable chair in a folded configuration.

A special 21-point electronic score device for games like Corn Hole. It is a portable, easy-to-see electronic scoreboard designed specifically for the popular backyard game of cornhole. It is made of durable materials with a fold-in base and includes 42 LEDs (21 on each side) stacked in the traditional score tower style that allows it to be used any time of day or night. It stands approximately fifty (50) inches high when in use and then can fold down to approximately thirty-six (36) inches for easy storage and portability. It has a handle for convenient carrying, a drink holder, and a compartment on top to hold a phone in place for video recording competitive games. The scoreboard can be used for any game played to 21 points.

A racquet includes a handle; and a frame connected to an end of the handle, the frame defining a rounded interior space, the frame including a negative Poisson's ratio (NPR) foam material, in which the NPR foam material, and in which the frame has a Poisson's ratio of between 0 and −1; and a network of strings stretched across the rounded interior space defined by the frame. A golf tee includes an elongated stem; and a head disposed at an end of the elongated stem and shaped to receive a golf ball; in which at least a portion of the golf tee is formed of a negative Poisson's ratio (NPR) foam material, in which the portion of the golf tee has a Poisson's ratio of between 0 and −1, and in which the NPR foam material includes an NPR metal foam, an NPR ceramic foam, or an NPR-PPR composite foam.

A rubber composition for a hollow ball includes a base rubber and an inorganic filler. A weight reduction rate TGA.sub.650 from room temperature to 650° C. and a weight reduction rate TGA.sub.850 from room temperature to 850° C. of the rubber composition are measured under an air atmosphere by thermogravimetry conforming to JIS K0129. The weight reduction rate TGA.sub.650 of the rubber composition is not less than 63% and not greater than 99%. A difference (TGA.sub.850−TGA.sub.650) between the weight reduction rates TGA.sub.850 and TGA.sub.650 of the rubber composition is not less than 0% and not greater than 7%. A hollow ball 2 includes a hollow core 4 formed from the rubber composition.

Disclosure of the present invention relates to an inverse “L” shaped tennis practice stand or device, which is installed on ground and is considerably higher than a person's height or to a wall-mountable tennis practice device, which is installed via bracket installed at a certain point at a house or building structure. In the tennis practice device according to the present invention, when a trainee hits the ball with a racket (racquet), the ball flies along a circumferential orbit/trajectory with weight or stopper, which is at an end of a horizontal pole, as the center point—that is the ball flies in the skyward direction in front (forward region) of the trainee and then returns to the same circumferential orbit/curve due to gravity, and the trainee practices tennis by repeatedly hitting the ball that falls in front of the trainee.

A grommet of a racket includes a tubular part. The tubular part includes a through hole through which a string is passed. The through hole includes a base opening, a side wall, and a non-circular tip opening. Assuming an imaginary dividing plane that is perpendicular to a face of the racket and that divides the non-circular tip opening into a first opening portion and a second opening portion shorter than the first opening portion in a direction parallel to the face, an inside dimension of the first opening portion in the direction perpendicular to the face increases gradually from one end of the non-circular tip opening in the direction parallel to the face to the dividing plane. In the tubular part, the string passes through the first opening portion and is in contact with the side wall from the base opening to the tip opening.